1. Field of the Invention
The present invention relates to a pulse laser used in, e.g., a YAG-laser and, more particularly, to an apparatus for instantaneously switching an optical path of light emitted from a laser medium by a light deflector to extract the switched light outside a laser resonator, and outputting the light as pulse laser light.
2. Related Background Art
Conventionally, in pulse oscillation of a YAG laser, a Q-switch, a cavity damper, a mode locker, and the like are used, and an A/O or E/O device is used as a deflector for these oscillator. In the A/O device, an ultrasonic wave is supplied to an acoustooptic crystal such as LiNbO.sub.3, PbMoO.sub.4, TeO.sub.2, or the like to bend emission light. The ultrasonic wave is repetitively supplied to instantaneously extract emission light from the laser medium outside a laser resonator at the same period as the ultrasonic wave, thereby outputting pulse laser light. In the E/O, a voltage is applied to an electrooptic crystal such as LiNbO.sub.3, KDP, ADP, or the like to bend emission light. The voltage is repetitively applied to instantaneously extract emission light, thereby outputting pulse laser light.
In the light deflector, so-called switching for deflecting emission light by repeating radiation of an ultrasonic wave or application of a voltage is the most important factor which determines the pulse width and peak power of laser light, because, a pulse laser apparatus requires high-speed switching.
Since the conventional light deflector supplies an ultrasonic wave or applies an electric field to an optical crystal, its high-speed operation as an optical switch for switching emission light is limited.